南陵县扬子鳄的种群数量及栖息地质量

198 6～ 1 998年 ,在安徽省南陵县对扬子鳄种群资源及分布区栖息地状况进行了 4次调查 ,1 999年对该县扬子鳄部分栖息地的质量做了研究。结果显示 ,南陵县扬子鳄野生种群目前只 30头左右 ,每 4年平均递减率约 38% ,分布于 6个镇 ,7个行政村中 ,75 %的栖息地已经消失。其中东河、三里、石铺三镇生活有全县 80 %的扬子鳄 ,而石铺镇扬子鳄密度最大。引起扬子鳄种群数量下降的主要原因是栖息地破坏 ,同时对鳄的捕杀、污染、天灾也是重要因素。其野外栖息地主要为两种类型 ,农耕区普通池塘和丘陵山地的山塘、水库。耕作区食物、栖息条件较好 ,人鳄矛盾较小的局部水域依然是扬子鳄最佳选择 ,但这类水域农药化肥污染已构成对扬子鳄的潜在威胁。

人工养殖扬子鳄野放初期的活动观察

20 0 3年 4月 2 7日 ,将经过兽医检查挑选出来的两雌一雄人工养殖的健康成年扬子鳄 (Alligatorsinensis)释放到安徽宣城红星扬子鳄保护点 ,利用无线电遥测技术测定其释放初期 4周内的活动区域 ,共记录3 72个位点 ;还通过白天望远镜观察和夜间灯光计数法观察了它们的活动情况。结果显示 :3条扬子鳄经过 3～1 4d后处于不同的稳定区域内 ,具领域特征 ;雄性个体的活动区域大于雌性 ,日活动区域面积的变化也大于雌性 ;局部环境选择上均趋向靠近岸边并具有茂密植被的区域。

温度对扬子鳄卵野外孵化的影响

Influence of temperature on egg incubation of the wild Chinese alligator was studied during the summer seasons of 1999 and 2000(July to October and August to September,respectively)at three observation sites, Zhuangtou of Xuanzhou County,Shuangkeng and Zhongqiao of Jingxian county, Anhui Province. One nest at each of the above sites was monitored, bearing 19,17 and 19 eggs,respectively. According to the width of the band on the eggs, we estimated the dates that the eggs were laid. We recorded both the nest temperature and atmosphere temperature with an automated temperature data logger (HOBO Temp) during the whole observation period.We found that the average nest temperature maintained around 25 26℃ during incubation throughout day and night,within over two thirds of time in each day the nest temperature being higher than the atmosphere temperature. Analysis of our data revealed that alligator nests have buffering effect on the inside temperature. Higher nest temperature (27 30℃)increased the hatching rate. It was also noticed that the hatching rate varied considerably from site to site(between 0 100%). We conclude that climate is an important factor influencing egg hatching in the wild, and prolonged rainy season which caused large temperature fluctuation can decrease the hatching rate of the alligator eggs.

扬子鳄卵不同部位中的Cu、Zn、Cd和Pb重金属元素分布

With two whole infertile eggs and two incomplete infertile eggs (having shell membrane and shell) of Chinese Alligator ( Alligator sinensis ) from the artificial condition and the field in Anhui Province,the authors studied the concentration of four heavy metal elements (Cu,Zn,Cd and Pb) in the different parts (albumen,yolk,shell membrane and shell) with Atomic Absorption Spectroscopy (AAS).Our results showed that these four elements’ concentration was quite different in the different parts of the same egg.The concentration of these four elements from high to low is Zn,Cu,Pb,Cd in the albumen,yolk and shell membrane of the infertile egg.However the sequence is Zn,Pb,Cu,Cd in the shell of the infertile egg.The concentration of Zn (the highest is 63 29?mg/kg) is higher than the other three elements in the same egg.The concentration of Cu (the highest is 20 03?mg/kg) is higher in the shell membrane than the others parts of the same egg.The concentration of Pb (the highest is 26 8?mg/kg) is higher in the shell than the other parts of the same egg.The concentration of Cd (the minimum is 0 024?mg/kg) is much lower than the other three elements in the albumen,yolk and shell membrane of the same egg.In addition,our results also showed that the concentration of these four elements tended higher in the infertile egg from the artificial condition than that from the field.The results should be considered by Chinese Alligator Breeding Center.

扬子鳄种群的线粒体DNA控制区序列变异性及其对物种保护的启示(英文)

测定了来自4个不同地点(包括安徽宣城野生和饲养种群、浙江长兴的饲养种群及在美国的饲养种群)的64个扬子鳄线粒体DNA控制区部分序列.结果共检测出4个单倍型共3个变异位点,与龟类、鸟类、哺乳类及其它鳄类相比较,反央出扬子鳄线粒体区的序列变异性很低.在此基础上,对扬子鳄遗传保护提出了有关建议.

鳄鱼拍档工作簿

时间过得真快,转眼就到了3月底4月初,冬眠的动物们纷纷苏醒,重返“江湖”!这些动物中特殊的一位,就是鳄鱼家族中具有冬眠习性的扬子鳄,它是我们中国的“特产”!睁开惺忪的睡眼,活动一下1.5米左右的身躯,爬出舒适的洞穴……哇,好明媚的阳光啊!

最后的土龙

鳄类是过去爬行动物统治地球时代一直延续到现在的代表。与鸟类一样．鳄类是从初龙（槽齿龙等古爬行类）演化而来且唯一存活至今的爬行动物类群．它们和很早前就已灭绝的恐龙有亲缘关系。一二十年前．人们担心这些经历了小行星撞击地球灾难而存活下来的物种会因遭到人类的猎杀而步恐龙的后尘。然而在今天．曾经一度严重威胁鳄类生存的猎杀活动已很大程度上被合法、有序管理的人工饲养繁殖所取代，鳄类不再身陷灭绝的处境。